As shown in FIG. 3, the invention relates to a sealing device for a fuel cell arrangement having a plurality of fuel cells combined to form a fuel cell stack (10), said fuel cells being permeable by the gas flows converted in the fuel cells transversely to the longitudinal direction of the fuel cell stack (10), and a gas distributor (20) provided on the longitudinal side of the fuel cell stack (10) for the supply and removal of the gas flows converted in the fuel cells, wherein the sealing device comprises a sealing frame (31) having a number of longitudinal sealing elements (32, 33, 34) disposed between the longitudinal edge of the gas distributor (20) and the fuel cell stack (10) and composed of a dielectric material, said sealing elements being may be disposed in a longitudinally movable fashion for the compensation of particularly thermally caused relative movements between the fuel cell stack and the gas distributor.
Fuel cell arrangements of the type for which the sealing device according to the invention is provided include a plurality of fuel cells combined to form a fuel cell stack, said fuel cells being permeable by the gas flows (fuel gas, oxidation gas, exhaust gas) converted in the fuel cells transversely to the longitudinal direction of the fuel cell stack. A gas distributor (manifold) is provided on the longitudinal side of the fuel cell stack for the supply and removal of the gas flows converted in the fuel cells, typically one gas distributor on two opposing longitudinal sides of the fuel cell stack. A sealing element, which mutually isolates these two elements, is provided between the fuel cell stack and the gas distributor. The sealing device traditionally includes a sealing frame, containing a number of longitudinal sealing elements disposed between the longitudinal edge of the gas distributor and the fuel cell stack and made from a dielectric material for electrical insulation.
When a fuel cell arrangement such as this is heated from ambient temperature to typically 650° C. or cooled, large changes in temperature can lead to significant relative movements of the dielectric sealing elements, so the elements are positioned between the fuel cell stack and the gas distributor in such a way that they are longitudinally movable to a certain degree, and able to absorb the relative movements. Usually, transverse sealing elements are positioned on the ends of the fuel cell stack between the transverse edges of the gas distributor and the fuel cell stack and they enclose the periphery of the sealing frame of the sealing device.